1. Field of the Invention
The present invention relates to a pesticide preparation (pesticide composition) and a process for producing the same.
2. Description of Related Art
The release control of a pesticide can be commonly achieved by microencapsulating a drug, coating a drug with a polymer material, or dispersing a drug in a water-insoluble preparation matrix (Non-Patent Literature 1).
For example, the methods for achieving sustained release by adding paraffin wax, a thermoplastic resin or activated carbon, a granular foam or a clay mineral in combination have been proposed (see Patent Literatures 1 to 3).
Further, Patent Literature 4 proposes a method for achieving sustained release by kneading a thermoplastic material and an inorganic diluent carrier under heating, cooling the obtained kneaded product and extruding it for granulation. The technique described in Patent Literature 4 adjusts the dissolution rate by kneading a hydrophobic wax and a hydrophilic wax. However, it requires the precise temperature control near the melting point to prevent the kneaded product from liquefying or separating into two layers. Furthermore, the cost for raw materials is presumably high since a large amount of waxes is contained.
Moreover, Patent Literature 5 proposes a method for achieving sustained release of an active ingredient, by using a cationic surfactant (amine salt-, pyridinium-, or quaternary ammonium salt-based surfactant, or the like) and an inorganic basic substance (calcium carbonate, or the like), for the purpose of controlling dissolution of a granular pesticide preparation containing a pesticide active ingredient. Examples of the amine cationic surfactant include long chain alkylamine salts (laurylamine chloride, stearylamine chloride, and the like).